On January 1, 2007, Oregon implemented its "Mental Health and Chemical Dependency Parity Legislation." Oregon's parity legislation differs in important ways from other parity expansions. The parity law is comprehensive in its definition of behavioral health (broadly defining mental health and including alcohol and drug abuse), and applies to any individual with commercial group insurance, except for those whose employers "self-insure." The changes affect coverage for a large proportion of Oregonians, which may lead to changes in practice patterns among the state's behavioral health providers. Perhaps most importantly, and in sharp contrast to previous research on parity, Oregon's law will be implemented without a migration to carve-outs for behavioral health care, without anticipated rate discounts for behavioral health providers, and without extensive use of strong managed care methods, such as gatekeeping, closed provider panels, or prior authorization. The overall goals of this application are to examine the effects of the comprehensive Oregon parity legislation on access and cost, using data from 6 commercial health plans, which comprise more than 70% of Oregon's commercial market. Our long term goal is to understand the relationship between expanding coverage of behavioral health services and total health care costs. The specific hypothesis behind the proposed research is that Oregon's parity legislation will improve patients'access to behavioral health care, but will lead to moderate increases in the total cost of care. The proposed research will clarify the extent to which comprehensive parity, in the absence of strong managed care, can be implemented without "breaking the bank." The application has two specific aims: Specific Aim 1. Assess the degree to which the Oregon parity legislation affects the use of services and cost of coverage. We will use statistical analyses of 4 years of claims data collected from 6 commercial health plans in Oregon to estimate the effect of the parity legislation on access, utilization, health plan spending per enrollee, and enrollee out-of pocket cost. Specific Aim 2. Examine the effect of Oregon's parity legislation on the provision and management of benefits for mental health and alcohol and drug abuse disorders. Specifically, we will use semi-structured interviews of key health plan personnel at 6 health plans to identify health plans'strategies for containing costs under the parity implementation. McConnell, KJ We propose to study Oregon's 2007 "parity" law, which mandates that private health insurers provide benefits for mental health and substance abuse treatment that are equal to the benefits for general medical care. Oregon's law is unique in its comprehensive definition of mental health and substance abuse and in its implementation in an environment without strong managed care. Our proposed research will provide insight about the tradeoffs between expanding coverage for mental health and substance abuse disorders and the total cost of care.